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Hello All,

I've just recently encountered a situation that I'm not sure what the cause may be and wanted to get some opinions. Maybe some of you have even seen this before.

On a recently completed project we installed about 24 26W compact flourescent recessed cans (Lithonia LX7F,120V ballast) in a corridor. The fixtures have a GE 4-pin Biax 26W CFL bulb installed. Initially we had a couple of bulbs burn out after about 2-weeks or so of operation. I thought maybe a couple of bad bulbs in the batch, so we replaced them. A week later there were two more burned out, different locations. I thought it was starting to get a little suspicious, but we replaced these two and watched. It's now been about 3 months and I continue to have these units burn out (up to a total of 7 so far). At $11 a pop I can't ignore that there maybe some weird problem on this particular circuit after all these things are suppose to last a long time 12000 Life Hours rating according to GE catalog. I find it hard to believe this is due to a poorly made product, if so GE would go out of business at this rate.

We have a couple other circuits with the same type of bulbs and fixtures and we haven't had this problem (yet).

What opinions do you have about this situation and any suggestions on what I should look for while troubleshooting.

Thanks

Not saying that this is the problem in your case, but...

I can’t afford to use GE anymore.
In the past, I had so many problems with GE incandescent A-19, BR-30, BR-40 and PAR-38 bulbs as well as their T12, HO and T5 fluorescent and MH tubes that I totally switched my stock over to Sylvania, Phillips and Feit. I have had almost no problems with faulty bulbs for well over three years now. Even the GE 12V/20W T-bulbs I used for Low-voltage undercabinet lighting were trash.
The last straw was when I had to go back within 2-weeks after finishing a job to replace three defective BR-30 bulbs for RC cans in a 17-foot ceiling, at my expense, of course.
No more GE for me!

Could the location be subjecting them to overheating?

Maybe so but also have to think about the ballast as well sometime we get new ballast be sour { bad } some case if that luminaire do have electronic ballast some of them just can't take the surge at all and smoke it as well.

Is the luminare running 24/7 ? if so check the supply voltage at daytime and again at nitetime to see if there is a diffrence sometime it can do it.

Merci,Marc

Oddly enough, I've also seen a disproportionate quantity of 26W fixtures that fail before their time. Problems such as:

- Ballasts burn out within the first 1 month to 1 year
- Lamps burn out within the first 1 month to 1 year

Advance ballast, work horse, etc, seem to all have the same issues.

I've been called out to brand new communities with 40+ of these fixtures, and the failure rate within the first 6 months is right around 15%. This would be unheard of with a twin PL-13 lamp and ballast installation, and in my opinion, is completely unacceptible (although having the business is nice )

I think perhaps this is an engineering issue with the lamp. Sensitive to their own heat output? Overly sensitive to vibration?

I would also love some answers on this.

Given that you are having issues with lights on a certain circuit, unless you just by chace got a bad batch of bulbs, I would start looking at the circuit. Maybe there is loose conncetion some where or it is somehow getting spiked. I would be looking at:

What is different about the questioned circuit compared to the other circuits that are similar?

What is the socket voltage on the troulbled circuit comepared to the other sockets one the good sockets?

What is the line voltage at the first and last light on a goood and bad circuit and the time of the day?

How is the power quality to the site?

If the neutrals is shared, what are they shared with?

Is the neutral properly shared all the way back to the panel?

Thanks for the replies so far. I know this is a topic of interest to everyone since most of the new projects are going to CFL's for recessed interior lighting.

The overheating comments are definately a good discussion topic. These CFL's are suppose to run cooler than incandescent, but I'll tell you these things are HOT! I have to let them cool down for a couple of minutes before I can handle them with my bare hands. I don't think the installation is prone to make them hot. The trims are full open clear specular finish, so they're probably going to be as cool as can be expected. The housing is dual Non-IC/IC rated and installed according to the manf. recommendations. There is no insulation covering the housings.

The run times on these fixtures are maybe 8 hours a day tops, usually less. They don't have lots of on/off switching, usually when switched on they will stay on for a reasonable amount of time before being switched off.

The wiring will definately be one of the first places I will check. The lights are on two 3-way switches, circuit is dedicated for the corridor lights only, no shared neutrals. Wiring is simple: 1. panel to switch box 1, 2. switch box to switch box No 2, and 3. Switch box 1 to fixtures. I would have thought other symptoms would be visually present in the lighting if I had bad wiring, but there could be something funny with the ground and neutral that might cause the ballast to function poorly. This circuit isn't really different from any other except maybe the three way switch, but again I have a couple other locations with three ways that aren't burning out like this one.

The power reliabilty to the site isn't the greatest, rural co-op, but nothing out of the ordinary for quality of power when it's working. I have TVSS on the main panel for larger surges. Grounding system is very good, UFER, Grounding grid, and structurally bonded to steel structure.

Hopefully that information will help with some of the comments and questions so far.

Good idea on having a TVSS in your system. That should protect you from spikes on outside sources. I can relate to power quality issues and CFL issues.

I checked everything on the circuit without tearing out every single light, but I found nothing. Everything checked out between the panel and the last fixture on the run. Continuity checks out, no shorts, voltage is good when energized. I'm baffled.

One thing I wonder about is the connectors on the fixtures. These fixtures had factory push-in type connectors on them and all of the wires are termininated to those connectors. Is it possible that a poor connection on one of these connectors is creating transients on the line and messing with the circuit? I would think if this was the case it would be visible in the fixture output by dimming or flickering or something like that.


Here is extra info about the 3-way switching scheme that maybe someone can comment on to see if you think anything is wrong here:

The first switch box contains the line conductors from the panel, the load conductors, and the travelers to the second three way switch box. There are 3 conductors and a ground to the 2nd three way, 1-hot leg and 2-return switch legs. (Note: the neutral does not extend through this 2nd three way switch box it only connects to the load neutral at the first box) I mention this because I'm wondering if that can have any effect on the circuit operation having different impedences on the hot conductor vs neutral conductor. This is a standard way to connect three ways and I've seen it done before without any problems, but I suppose I'm grasping for straws at this point. Does anyone see a problem with that?

Thanks for the input.

If you are really seeing that much heat it sounds like a design problem. The whole idea of a can is you use a reflector bulb that sends most of the heat down, out of the can. Maybe the actual hot spot in a CFL is not anywhere near the focal point of the reflector. I would almost say I am sure of it.BTW as an aside, I am having 100% luck with the normal spiral bulbs and I am just getting cheap ones from Sams and Home Depot when they are on sale. I am coming up on 2 years on the ones in my garage and out in the post light. (all on motion detectors)